A potential field survey is performed by measuring potential field data which, for a gravity survey, may comprise one or more of gravimeter data (measuring gravity field) or gravity gradiometer data (measuring gravity field gradient), vector magnetometer data, true magnetic gradiometer data, and other types of data well-known to those skilled in the art. A common aim of a geophysical potential field survey is to search for signatures which potentially indicate valuable mineral deposits.
The goal of most potential field surveys is to deduce the sub-surface geology. It is well known to the geophysics industry that the high spatial frequency potential field signals are dominated by near surface anomalies. Further, in most situations, the terrain and the near surface geology also give rise to substantial low spatial frequency signals. In general, the low frequency signals from the near surface anomalies are extremely hard to distinguish from the low frequency signals coming from deeper geology. Accordingly, it is possible to postulate a geology having only a near surface mass distribution which matches the measured signal implying that there are no anomalies left in the measured signal coming from deep geologies. Fortunately most such mass distributions can be ruled out using a range of tools including geological knowledge, known typical density distributions, prior information, similar known structures elsewhere in the world etc.
There remains a need, however, for improved techniques for processing geophysical data from such surveys in order to identify the underlying geology.